This invention relates to engine starters in general and, in particular, to an engine starter of the hybrid type comprising both an electric motor and a hand reel which lend themselves to selective use for power starting or manual starting of the engine. The engine starter in accordance with the invention finds a typical application to general purpose engines.
Both manual and motor driven starters have been suggested and used extensively for cranking general purpose engines. Japanese Laid Open Utility Model Application No. 59-56377 discloses an example of a motor driven starter. It comprises an electric starting motor having its armature shaft geared to an engine crankshaft via an overrunning clutch. An objection to this known power starter is that it becomes totally inoperable in the event of a failure of the battery which is normally employed for powering the starting motor.
This inconvenience is absent from manual starters, an example of which is found in Japanese Utility Model Publication No. 57-55969. This prior art manual starter has a starting reel, with a pull rope wound thereon, which is coupled to a flywheel on an engine crankshaft via an automatic clutch. Upon exertion of a pull on the pull rope the automatic clutch will engage to transmit the rotation of the starting reel to the engine crankshaft. Although practically trouble free, the manual starter is inherently objectionable because of the manual labor involved.
An obvious solution to the problem of how to preclude the weaknesses of both types of starters is to provide a hybrid device comprising both a starting motor and a starting reel, so that the engine may be started either by power cranking or by hand cranking. This concept is itself not new but is embodied, for example, in the device described and claimed in Japanese Laid Open Utility Model Application No. 58-108239. This prior art device is unsatisfactory, however, because of its large bulk resulting from the totally independent connection of the power cranking mechanism and the manual cranking mechanism to the engine crankshaft.